I should have clarified what I meant. I clean the aluminum with alcohol or Lysol wipes. The screen, I use a micro fiber with screen cleaner or just a mist of water.
The aluminium on the Mac is anodized to protect it against the elements including cleaning solvents. However it's not recommended to use abrasive solutions; some things like the sweat on your hands can cause pitting in aluminium, so just be sure to wipe it down once in a while.
Also don't use sandpaper or scrubbing pads.
I usually use rubbing alcohol with a paper towel as it both cleans and disinfects.